1. Field of the Invention
The present invention relates to a non-contact charge and communication system including a non-contact charge system and a wireless communication system that transmit and receive power in a non-contact (wireless) manner.
2. Description of the Related Art
The electromagnetic induction system is known as a system for non-contact (wireless) supply of power.
Furthermore, in recent years, wireless power feed and charge systems employing a system called the magnetic field resonance system based on the electromagnetic resonance phenomenon are attracting attention.
Presently, in the non-contact power feed system based on the electromagnetic induction system, which has been already widely used, the power feed source and the power feed target (power receiving side) have to share magnetic flux. Therefore, the power feed source and the power feed target have to be disposed very close to each other for power sending with high efficiency, and axis alignment of the coupling is also important.
In contrast, the non-contact power feed system employing the electromagnetic resonance phenomenon has advantages that power can be transmitted across a longer distance compared with the electromagnetic induction system and the transmission efficiency is not greatly lowered even when the accuracy of axis alignment is somewhat low, because of the principle of the electromagnetic resonance phenomenon.
Besides the magnetic field resonance system, the electric field resonance system is also known as the system based on the electromagnetic resonance phenomenon.
A wireless power feed system employing this magnetic field resonance system requires no axis alignment and enables extension of the power feed distance.
Such a wireless power feed system can be used as e.g. a charge service station for a non-contact charge of a portable terminal such as an individually-owned cellular phone at a public place.
The following problems may exist when the charge service station at a public place is assumed.
It is troublesome to collect a small charge fee from the user each time.
The user does not realize much convenience if a charge is a pay service.
It is difficult to spread the charge service stations at public places unless there is not only a user's merit that a portable terminal can be charged but also a merit for the facility side that provides the charge service.
A technique disclosed in Japanese Patent Laid-open No. 2008-295191 has been proposed as a technique to solve the above-described problems.
This technique employs a system in which one coil is shared by a non-contact communication system and a non-contact charge system and non-contact communication and non-contact charge are carried out separately from each other in a time-division manner.